Antimicrobial materials exhibiting synergistic efficacy

ABSTRACT

Embodiments of the present invention pertain to a material including a carrier and a co-biocide including copper ions and a biocide such as ZnPT, Tralopyril or a combination thereof. The material may include a copper-containing glass particles or cuprous oxide particles. In some embodiments, the copper-containing glass may include glass phase and a cuprite phase. In other embodiments, the copper-containing glass may include as plurality of Cu1+ ions, a degradable phase including B2O3, P2O5 and K2O and a durable phase including SiO2. In some embodiments, the carrier is a paint.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage entry of International PatentApplication Serial No. PCT/US16/30341 filed on May 2, 2016, which claimsthe benefit of priority under 35 U.S.C. § 119 of U.S. ProvisionalApplication Ser. No. 62/185,317 filed on Jun. 26, 2015, and U.S.Provisional Application Ser. No. 62/157,117 filed on May 2, 2015, thecontent of which is relied upon and incorporated herein by reference inits entirety.

BACKGROUND

The disclosure relates to antimicrobial materials, and more particularlyto antimicrobial materials comprising a co-biocide of copper ions andzinc pyrithione.

Biocides are commonly added to paint formulations and other carriers tomaintain such products' integrity from microbial attack and to preventfungal and algal growth in the dry film. A common commercial biocide iszinc pyrithione. Zinc pyrithione (ZnPT) is widely applied in conjunctionwith copper (Cu) in antifouling paints as a substitute for tributyltin.Typical use level of ZnPT for dry film fungicide is around 1% by weight;however in combination with Cu, ZnPT has shown algaecide activity inconcentration range of 1-100 ppm (μg/L).

Another common commercial biocide is Tralopyril(4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile).Tralopyril is an antifouling agent for use in antifouling coatings to beapplied on ship hulls or other marine structures; however, its activityagainst bacteria is not sufficient.

There is a need for maintaining such dry film fungicide activity butusing lower concentrations of copper and/or lower concentrations of ZnPT(e.g., 15 mg/Gal of ZnPT), Tralopyril or a combination thereof.

SUMMARY

Various aspects of this disclosure pertain to an antimicrobial materialthat exhibits a synergistic effect with respect to microbes such asfungi. In one or more embodiments, the material includes a co-biocide ofcopper ions and either one of ZnPT and Tralopyril. In some embodiments,the copper ions are present in the form of copper-containing particles.Suitable copper-containing particles may include either one or both ofcopper-containing glass and cuprous oxide. In one or more embodiments,the copper-containing particles release Cu¹⁺ ions in a continuousmanner, without additional treatment or steps to maintain oxidationstate. It should be noted that known copper materials and ZnPT aloneshowed no inhibition of fungi. Without being bound by theory, it isbelieved that such synergistic effect is partially attributable to theformation of CuPT by transchelation of ZnPT with Cu. CuPT has been shownto be more toxic than ZnPT to marine organisms and here the embodimentsdescribed herein demonstrate CuPT may have the same effect againstfungi.

A first aspect relates a material including a carrier, a co-biocideincluding a plurality of copper ions or copper-containing particles andeither one or both of ZnPT and Tralopyril. The carrier may include apolymer, a monomer, a binder or a solvent. In some embodiments, thecarrier is a paint. In some instances, the ratio of thecopper-containing particles (g) per gallon of carrier and either one ofZnPT (g) and Tralopyril (g) per gallon of carrier is in the range fromabout 0.005 to about 12. In some embodiments, ZnPT is present in a rangefrom about 150 mg/gallon of carrier to about 40 g/gallon of carrier. Thematerial may include excess ZnPT and thus may include Zn.

The copper-containing particles may be present as copper-containingglass particles and/or cuprous oxide particles. The copper-containingparticles may be present in an amount of about 20 g/gallon or less.

A second aspect of this disclosure pertains to a paint including thecarrier and co-biocide as described above. In some embodiments, afterthe paint is applied to a surface as a layer, the layer exhibits, in theCIE L*a*b* system, an L* value in the range from about 94 to about 100,and a DELTA E value of less than about 5, wherein DELTA E equals√(L*²+a*²+b*²). In some instances the layer exhibits no mold or fungigrowth, under ASTM 5590.

In one or more embodiments, the article provides durable antimicrobialactivity, which is demonstrated by controlled and prolonged release ofboth ZnPT and Cu¹⁺ ions. The synergistic effect of such embodimentspermits the use of these materials at a reduced concentration, therebyminimizing the cost.

In some embodiments, the antimicrobial material that is cost effective,while being less toxic due to lower concentration of active agents. Theantimicrobial material also reduces the risk of biocide resistance

Additional features and advantages will be set forth in the detaileddescription which follows, and in part will be readily apparent to thoseskilled in the art from that description or recognized by practicing theembodiments as described herein, including the detailed descriptionwhich follows, the claims, as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are merely exemplary, and areintended to provide an overview or framework to understanding the natureand character of the claims. The accompanying drawings are included toprovide a further understanding, and are incorporated in and constitutea part of this specification. The drawings illustrate one or moreembodiment(s), and together with the description serve to explainprinciples and operation of the various embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the effect of the amount of biocide on moldgrowth according to Example 2;

FIG. 2 is a graph showing the effect of the amount of biocide on mildewgrowth according to Example 2; and

FIG. 3 is shows fungi resistance of under ASTM 5590 according to Example4.

DETAILED DESCRIPTION

Reference will now be made in detail to the present preferredembodiment(s), examples of which are illustrated in the accompanyingdrawings. Various aspects of this disclosure pertains to a colorlessmaterial that exhibits a white or colorless appearance, andantimicrobial activity that meets the health benefit requirements setforth by the United States Environmental Protection Agency (EPA).Specifically, the material exhibits a kill rate of greater than 99.9%(or a log reduction of 3 or greater) within 2 hours of exposure toStaphylococcus aureus under the EPA Test Method for Efficacy of CopperAlloy as a Sanitizer testing conditions (the “EPA Test”). In someembodiments, the material kills fungi (e.g., A. pullulans and A.niger/P. funiculosum) under ASTM 5590. In some embodiments, the materialkills such fungi under a zone of inhibition test, as described herein

As used herein the term “antimicrobial,” means a material, or a surfaceof a material that will kill or inhibit the growth of microbes includingbacteria, viruses and/or fungi. The term as used herein does not meanthe material or the surface of the material will kill or inhibit thegrowth of all species microbes within such families, but that it willkill or inhibit the growth or one or more species of microbes from suchfamilies.

As used herein the term “log reduction” means—log (C_(a)/C₀), whereCa=the colony form unit (CFU) number of the antimicrobial surface andC₀=the colony form unit (CFU) of the control surface that is not anantimicrobial surface. As an example, a 3 log reduction equals about99.9% of the microbes killed and a Log Reduction of 5=99.999% ofmicrobes killed.

A first aspect of this disclosure pertains to a material including acarrier and a co-biocide including a plurality of copper ions and eitherone or both ZnPT and Tralopyril. In one or more embodiments, thematerial can be characterized as colorless under the CIE L*a*b*colorimetry system. In one or more embodiments, the material exhibits anL* value in the range from about 88 to about 100 (e.g., from about 90 toabout 100, from about 91 to about 100, from about 92 to about 100, fromabout 93 to about 100, from about 94 to about 100, from about 88 toabout 98, from about 88 to about 96, from about 88 to about 95, or fromabout 88 to about 94). In one or more embodiments, the material exhibitsa DELTA E value of less than about 10, wherein DELTA E equals√(L*²+a*²+b*²). The DELTA E value exhibited by the material of one ormore embodiment may be less than about 9, less than about 8, less thanabout 7, less than about 6, less than about 5 or less than about 4. Insome instances, the DELTA E value may even be less than about 3 or 2.The L*, a*, and b* values described herein are measured at normalincidence using a standard illuminant as determined by the CIE,including an A illuminant (representing tungsten-filament lighting), Billuminant (representing daylight simulating illuminants), C illuminant(representing daylight simulating illuminants), D illuminant(representing natural daylight), and F illuminant (representing varioustypes of fluorescent lighting). In some embodiments, the L*, a*, and b*values described herein are measured under CIE D65 of F2 illuminant.

In some embodiments, the material exhibits the L*, a*, and b* valuesdescribed herein after application of the material on a surface as alayer. In specific embodiments, the resulting layer exhibits the L*, a*,and b* values described herein. In such embodiments, the material mayinclude titanium dioxide and exhibits the L*, a*, and b* valuesdescribed herein after application of the material to a surface (e.g.,about 2 minutes after formation of the layer, 5 minutes after formationof the layer or about 10 minutes or more after formation of the layer).In some embodiments, the layer becomes whiter or more colorless withtime. In some instances, the L*, a*, and b* values described herein areexhibited after about 20 minutes, after 30 minutes, after 45 minutes,after 60 minutes, after the formation of the layer. The L*, a*, and b*values are exhibited after drying in air and without any post treatment(e.g., exposure to ultra-violet light etc.).

In one or more embodiments, the material exhibits a whiter or morecolorless appearance immediately after combination. For example, in someembodiments, material stored for one week or more (without applicationto a surface) appeared white and colorless.

In one or more embodiments, the material exhibits a greater than 3 logreduction in a concentration of Staphylococcus aureus, under the EPATest.

In one or more embodiments, the material may exhibit a 2 log reductionor greater (e.g., 4 log reduction or greater, or a 5 log reduction orgreater) in a concentration of Murine Norovirus, under modified JIS Z2801 (2000) testing conditions for evaluating viruses (hereinafter,“Modified JIS Z 2801 for Viruses”). The Modified JIS Z 2801 (2000) Testfor Viruses is described in greater detail herein.

In some embodiments, the material may exhibit the log reductionsdescribed herein (i.e., under the EPA Test, the Modified JIS Z 2801 Testfor Bacteria and/or the Modified JIS Z 2801 Test for Viruses), for aperiod of one month or greater or for a period of three months orgreater. The one month period or three month period may commence at orafter the application of the material to a surface as a layer. In suchthe layer exhibits the log reductions described herein.

In one or more embodiments, the ratio of the copper ions (g) and eitherone or both of ZnPT (g) and Tralopyril (g) per gallon of carrier is inthe range from about 0.005 to about 12 (e.g., in the range from about0.01 to about 12, from about 0.05 to about 12, from about 0.1 to about12, from about 0.5 to about 12, from about 1 to about 12, from about0.005 to about 10, from about 0.005 to about 8, from about 0.005 toabout 6, from about 0.005 to about 5, from about 0.005 to about 4, fromabout 0.005 to about 3, or from about 0.005 to about 2).

In one or more embodiments, the ZnPT is present in a range from about150 mg/gallon of carrier to about 40 g/gallon of carrier. In one or moreembodiments, the amount of ZnPT in the material is in the range fromabout 150 mg/gallon to 38 g/gallon, from about 150 mg/gallon to 36g/gallon, from about 150 mg/gallon to 35 g/gallon, from about 150mg/gallon to 34 g/gallon, from about 150 mg/gallon to 30 g/gallon, fromabout 150 mg/gallon to 28 g/gallon, from about 150 mg/gallon to 26g/gallon, from about 150 mg/gallon to 24 g/gallon, from about 150mg/gallon to 22 g/gallon, from about 150 mg/gallon to 20 g/gallon, fromabout 150 mg/gallon to 15 g/gallon, from about 150 mg/gallon to 10g/gallon, from about 500 mg/gallon to 40 g/gallon, from about 1 g/gallonto 40 g/gallon, from about 2 g/gallon to 40 g/gallon, from about 4g/gallon to 40 g/gallon, from about 5 g/gallon to 40 g/gallon, fromabout 6 g/gallon to 40 g/gallon, from about 8 g/gallon to 40 g/gallon,from about 10 g/gallon to 40 g/gallon, or from about 1 g/gallon to 10g/gallon. In some embodiments, the material includes ZnPT in an excessamount such that both Zn and ZnPT are present in the material.

In one or more embodiments, the Tralopyril is present in a range fromabout 150 mg/gallon of carrier to about 40 g/gallon of carrier.

-   -   When both ZnPT and Tralopyril are utilized, the amount of both        ZnPT and Tralopyril may be in the range from about 150 mg/gallon        of carrier to about 40 g/gallon of carrier.

In one or more embodiments, the material includes copper-containingparticles. Examples of copper-containing particles include either one orboth of copper-containing glass and cuprous oxide. In some instances,the copper-containing particles include only copper-containing glass oronly cuprous oxide.

One or more embodiments of the copper-containing glass include a Cuspecies. In one or more alternative embodiments, the Cu species mayinclude Cu¹⁺, Cu⁰, and/or Cu²⁺. The combined total of the Cu species maybe about 10 wt % or more. However, as will be discussed in more detailbelow, the amount of Cu²⁺ is minimized or is reduced such that thecopper-containing glass is substantially free of Cu²⁺. The Cu¹⁺ ions maybe present on or in the surface and/or the bulk of the copper-containingglass. In some embodiments, the Cu¹⁺ ions are present in a glass networkand/or a glass matrix of the copper-containing glass. Where the Cu¹⁺ions are present in the glass network, the Cu¹⁺ ions are atomicallybonded to the atoms in the glass network. Where the Cu¹⁺ ions arepresent in the glass matrix, the Cu¹⁺ ions may be present in the form ofCu¹⁺ crystals that are dispersed in the glass matrix. In someembodiments the Cu¹⁺ crystals include cuprite (Cu₂O). In suchembodiments, where Cu¹⁺ crystals are present, the material may bereferred to as a copper-containing glass ceramic, which is intended torefer to a specific type of glass with crystals that may or may not besubjected to a traditional ceramming process by which one or morecrystalline phases are introduced and/or generated in the glass. Wherethe Cu¹⁺ ions are present in a non-crystalline form, the material may bereferred to as a copper-containing glass. In some embodiments, both Cu¹⁺crystals and Cu¹⁺ ions not associated with a crystal are present in thecopper-containing glasses described herein.

In one or more embodiments, the copper-containing glass may be formedfrom a glass composition that can include, in mole percent, SiO₂ in therange from about 30 to about 70, Al₂O₃ in the range from about 0 toabout 20, a copper-containing oxide in the range from about 10 to about50, CaO in the range from about 0 to about 15, MgO in the range fromabout 0 to about 15, P₂O₅ in the range from about 0 to about 25, B₂O₃ inthe range from about 0 to about 25, K₂O in the range from about 0 toabout 20, ZnO in the range from about 0 to about 5, Na₂O in the rangefrom about 0 to about 20, and/or Fe₂O₃ in the range from about 0 toabout 5. In such embodiments, the amount of the copper-containing oxideis greater than the amount of Al₂O₃. In some embodiments, the glasscomposition may include a content of R₂O, where R may include K, Na, Li,Rb, Cs and combinations thereof.

In the embodiments of the glass compositions described herein, SiO₂serves as the primary glass-forming oxide. The amount of SiO₂ present ina glass composition should be enough to provide glasses that exhibit therequisite chemical durability suitable for its use or application (e.g.,touch applications, article housing etc.). The upper limit of SiO₂ maybe selected to control the melting temperature of the glass compositionsdescribed herein. For example, excess SiO₂ could drive the meltingtemperature at 200 poise to high temperatures at which defects such asfining bubbles may appear or be generated during processing and in theresulting glass. Furthermore, compared to most oxides, SiO₂ decreasesthe compressive stress created by an ion exchange process of theresulting glass. In other words, glass formed from glass compositionswith excess SiO₂ may not be ion-exchangeable to the same degree as glassformed from glass compositions without excess SiO₂. Additionally oralternatively, SiO₂ present in the glass compositions according to oneor more embodiments could increase the plastic deformation prior breakproperties of the resulting glass. An increased SiO₂ content in theglass formed from the glass compositions described herein may alsoincrease the indentation fracture threshold of the glass.

In one or more embodiments, the glass composition includes SiO₂ in anamount, in mole percent, in the range from about 30 to about 70, fromabout 30 to about 69, from about 30 to about 68, from about 30 to about67, from about 30 to about 66, from about 30 to about 65, from about 30to about 64, from about 30 to about 63, from about 30 to about 62, fromabout 30 to about 61, from about 30 to about 60, from about 40 to about70, from about 45 to about 70, from about 46 to about 70, from about 48to about 70, from about 50 to about 70, from about 41 to about 69, fromabout 42 to about 68, from about 43 to about 67 from about 44 to about66 from about 45 to about 65, from about 46 to about 64, from about 47to about 63, from about 48 to about 62, from about 49 to about 61, fromabout 50 to about 60 and all ranges and sub-ranges therebetween.

In one or more embodiments, the glass composition includes Al₂O₃ anamount, in mole percent, in the range from about 0 to about 20, fromabout 0 to about 19, from about 0 to about 18, from about 0 to about 17,from about 0 to about 16, from about 0 to about 15, from about 0 toabout 14, from about 0 to about 13, from about 0 to about 12, from about0 to about 11 from about 0 to about 10, from about 0 to about 9, fromabout 0 to about 8, from about 0 to about 7, from about 0 to about 6,from about 0 to about 5, from about 0 to about 4, from about 0 to about3, from about 0 to about 2, from about 0 to about 1, from about 0.1 toabout 1, from about 0.2 to about 1, from about 0.3 to about 1 from about0.4 to about 1 from about 0.5 to about 1, from about 0 to about 0.5,from about 0 to about 0.4, from about 0 to about 0.3 from about 0 toabout 0.2, from about 0 to about 0.1 and all ranges and sub-rangestherebetween. In some embodiments, the glass composition issubstantially free of Al₂O₃. As used herein, the phrase “substantiallyfree” with respect to the components of the glass composition and/orresulting glass means that the component is not actively orintentionally added to the glass compositions during initial batching orsubsequent post processing (e.g., ion exchange process), but may bepresent as an impurity. For example, a glass composition, a glass may bedescribe as being substantially free of a component, when the componentis present in an amount of less than about 0.01 mol %.

The amount of Al₂O₃ may be adjusted to serve as a glass-forming oxideand/or to control the viscosity of molten glass compositions. Withoutbeing bound by theory, it is believed that when the concentration ofalkali oxide (R₂O) in a glass composition is equal to or greater thanthe concentration of Al₂O₃, the aluminum ions are found in tetrahedralcoordination with the alkali ions acting as charge-balancers. Thistetrahedral coordination greatly enhances various post-processing (e.g.,ion exchange process) of glasses formed from such glass compositions.Divalent cation oxides (RO) can also charge balance tetrahedral aluminumto various extents. While elements such as calcium, zinc, strontium, andbarium behave equivalently to two alkali ions, the high field strengthof magnesium ions causes them to not fully charge balance aluminum intetrahedral coordination, resulting in the formation of five- andsix-fold coordinated aluminum. Generally, Al₂O₃ can play an importantrole in ion-exchangeable glass compositions and strengthened glassessince it enables a strong network backbone (i.e., high strain point)while allowing for the relatively fast diffusivity of alkali ions.However, when the concentration of Al₂O₃ is too high, the glasscomposition may exhibit lower liquidus viscosity and, thus, Al₂O₃concentration may be controlled within a reasonable range. Moreover, aswill be discussed in more detail below, excess Al₂O₃ has been found topromote the formation of Cu²⁺ ions, instead of the desired Cu¹⁺ ions.

In one or more embodiments, the glass composition includes acopper-containing oxide in an amount, in mole percent, in the range fromabout 10 to about 50, from about 10 to about 49, from about 10 to about48, from about 10 to about 47, from about 10 to about 46, from about 10to about 45, from about 10 to about 44, from about 10 to about 43, fromabout 10 to about 42, from about 10 to about 41, from about 10 to about40, from about 10 to about 39, from about 10 to about 38, from about 10to about 37, from about 10 to about 36, from about 10 to about 35, fromabout 10 to about 34, from about 10 to about 33, from about 10 to about32, from about 10 to about 31, from about 10 to about 30, from about 10to about 29, from about 10 to about 28, from about 10 to about 27, fromabout 10 to about 26, from about 10 to about 25, from about 10 to about24, from about 10 to about 23, from about 10 to about 22, from about 10to about 21, from about 10 to about 20, from about 11 to about 50, fromabout 12 to about 50, from about 13 to about 50, from about 14 to about50, from about 15 to about 50, from about 16 to about 50, from about 17to about 50, from about 18 to about 50, from about 19 to about 50, fromabout 20 to about 50, from about 10 to about 30, from about 11 to about29, from about 12 to about 28, from about 13 to about 27, from about 14to about 26, from about 15 to about 25, from about 16 to about 24, fromabout 17 to about 23, from about 18 to about 22, from about 19 to about21 and all ranges and sub-ranges therebetween. In one or more specificembodiments, the copper-containing oxide may be present in the glasscomposition in an amount of about 20 mole percent, about 25 molepercent, about 30 mole percent or about 35 mole percent. Thecopper-containing oxide may include CuO, Cu₂O and/or combinationsthereof.

The copper-containing oxides in the glass composition form the Cu¹⁺ ionspresent in the resulting glass. Copper may be present in the glasscomposition and/or the glasses including the glass composition invarious forms including Cu⁰, Cu¹⁺ and Cu²⁺. Copper in the Cu⁰ or Cu¹⁺forms provide antimicrobial activity. However forming and maintainingthese states of antimicrobial copper are difficult and often, in knownglass compositions, Cu²⁺ ions are formed instead of the desired Cu⁰ orCu¹⁺ ions.

In one or more embodiments, the amount of copper-containing oxide isgreater than the amount of Al₂O₃ in the glass composition. Without beingbound by theory it is believed that an about equal amount ofcopper-containing oxides and Al₂O₃ in the glass composition results inthe formation of tenorite (CuO) instead of cuprite (Cu₂O). The presenceof tenorite decreases the amount of Cu¹⁺ in favor of Cu²⁺ and thus leadsto reduced antimicrobial activity. Moreover, when the amount ofcopper-containing oxides is about equal to the amount of Al₂O₃, aluminumprefers to be in a four-fold coordination and the copper in the glasscomposition and resulting glass remains in the Cu²⁺ form so that thecharge remains balanced. Where the amount of copper-containing oxideexceeds the amount of Al₂O₃, then it is believed that at least a portionof the copper is free to remain in the Cu¹⁺ state, instead of the Cu²⁺state, and thus the presence of Cu¹⁺ ions increases.

The glass composition of one or more embodiments includes P₂O₅ in anamount, in mole percent, in the range from about 0 to about 25, fromabout 0 to about 22, from about 0 to about 20, from about 0 to about 18,from about 0 to about 16, from about 0 to about 15, from about 0 toabout 14, from about 0 to about 13, from about 0 to about 12, from about0 to about 11, from about 0 to about 10, from about 0 to about 9, fromabout 0 to about 8, from about 0 to about 7, from about 0 to about 6,from about 0 to about 5, from about 0 to about 4, from about 0 to about3, from about 0 to about 2, from about 0 to about 1, from about 0.1 toabout 1, from about 0.2 to about 1, from about 0.3 to about 1 from about0.4 to about 1 from about 0.5 to about 1, from about 0 to about 0.5,from about 0 to about 0.4, from about 0 to about 0.3 from about 0 toabout 0.2, from about 0 to about 0.1 and all ranges and sub-rangestherebetween. In some embodiments, the glass composition includes about10 mole percent or about 5 mole percent P₂O₅ or, alternatively, may besubstantially free of P₂O₅.

In one or more embodiments, P₂O₅ forms at least part of a less durablephase or a degradable phase in the glass. The relationship between thedegradable phase(s) of the glass and antimicrobial activity is discussedin greater detail herein. In one or more embodiments, the amount of P₂O₅may be adjusted to control crystallization of the glass compositionand/or glass during forming. For example, when the amount of P₂O₅ islimited to about 5 mol % or less or even 10 mol % or less,crystallization may be minimized or controlled to be uniform. However,in some embodiments, the amount or uniformity of crystallization of theglass composition and/or glass may not be of concern and thus, theamount of P₂O₅ utilized in the glass composition may be greater than 10mol %.

In one or more embodiments, the amount of P₂O₅ in the glass compositionmay be adjusted based on the desired damage resistance of the glass,despite the tendency for P₂O₅ to form a less durable phase or adegradable phase in the glass. Without being bound by theory, P₂O₅ candecrease the melting viscosity relative to SiO₂. In some instances, P₂O₅is believed to help to suppress zircon breakdown viscosity (i.e., theviscosity at which zircon breaks down to form ZrO₂) and may be moreeffective in this regard than SiO₂. When glass is to be chemicallystrengthened via an ion exchange process, P₂O₅ can improve thediffusivity and decrease ion exchange times, when compared to othercomponents that are sometimes characterized as network formers (e.g.,SiO₂ and/or B₂O₃).

The glass composition of one or more embodiments includes B₂O₃ in anamount, in mole percent, in the range from about 0 to about 25, fromabout 0 to about 22, from about 0 to about 20, from about 0 to about 18,from about 0 to about 16, from about 0 to about 15, from about 0 toabout 14, from about 0 to about 13, from about 0 to about 12, from about0 to about 11, from about 0 to about 10, from about 0 to about 9, fromabout 0 to about 8, from about 0 to about 7, from about 0 to about 6,from about 0 to about 5, from about 0 to about 4, from about 0 to about3, from about 0 to about 2, from about 0 to about 1, from about 0.1 toabout 1, from about 0.2 to about 1, from about 0.3 to about 1 from about0.4 to about 1 from about 0.5 to about 1, from about 0 to about 0.5,from about 0 to about 0.4, from about 0 to about 0.3 from about 0 toabout 0.2, from about 0 to about 0.1 and all ranges and sub-rangestherebetween. In some embodiments, the glass composition includes anon-zero amount of B₂O₃, which may be, for example, about 10 molepercent or about 5 mole percent. The glass composition of someembodiments may be substantially free of B₂O₃.

In one or more embodiments, B₂O₃ forms a less durable phase or adegradable phase in the glass formed form the glass composition. Therelationship between the degradable phase(s) of the glass andantimicrobial activity is discussed in greater detail herein. Withoutbeing bound by theory, it is believed the inclusion of B₂O₃ in glasscompositions imparts damage resistance in glasses incorporating suchglass compositions, despite the tendency for B₂O₃ to form a less durablephase or a degradable phase in the glass. The glass composition of oneor more embodiments includes one or more alkali oxides (R₂O) (e.g.,Li₂O, Na₂O, K₂O, Rb₂O and/or Cs₂O). In some embodiments, the alkalioxides modify the melting temperature and/or liquidus temperatures ofsuch glass compositions. In one or more embodiments, the amount ofalkali oxides may be adjusted to provide a glass composition exhibitinga low melting temperature and/or a low liquidus temperature. Withoutbeing bound by theory, the addition of alkali oxide(s) may increase thecoefficient of thermal expansion (CTE) and/or lower the chemicaldurability of the copper-containing glasses that include such glasscompositions. In some cases these attributes may be altered dramaticallyby the addition of alkali oxide(s).

In some embodiments, the copper-containing glasses disclosed herein maybe chemically strengthened via an ion exchange process in which thepresence of a small amount of alkali oxide (such as Li₂O and Na₂O) isrequired to facilitate ion exchange with larger alkali ions (e.g., K⁺),for example exchanging smaller alkali ions from an copper-containingglass with larger alkali ions from a molten salt bath containing suchlarger alkali ions. Three types of ion exchange can generally be carriedout. One such ion exchange includes a Nat for-Li⁺ exchange, whichresults in a deep depth of layer but low compressive stress. Anothersuch ion exchange includes a K⁺ for-Li⁺ exchange, which results in asmall depth of layer but a relatively large compressive stress. A thirdsuch ion exchange includes a K⁺ for-Na⁺ exchange, which results inintermediate depth of layer and compressive stress. A sufficiently highconcentration of the small alkali oxide in glass compositions may benecessary to produce a large compressive stress in the copper-containingglass including such glass compositions, since compressive stress isproportional to the number of alkali ions that are exchanged out of thecopper-containing glass.

In one or more embodiments, the glass composition includes K₂O in anamount in the range from about 0 to about 20, from about 0 to about 18,from about 0 to about 16, from about 0 to about 15, from about 0 toabout 14, from about 0 to about 13, from about 0 to about 12, from about0 to about 11, from about 0 to about 10, from about 0 to about 9, fromabout 0 to about 8, from about 0 to about 7, from about 0 to about 6,from about 0 to about 5, from about 0 to about 4, from about 0 to about3, from about 0 to about 2, from about 0 to about 1, from about 0.1 toabout 1, from about 0.2 to about 1, from about 0.3 to about 1 from about0.4 to about 1 from about 0.5 to about 1, from about 0 to about 0.5,from about 0 to about 0.4, from about 0 to about 0.3 from about 0 toabout 0.2, from about 0 to about 0.1 and all ranges and sub-rangestherebetween. In some embodiments, the glass composition includes anon-zero amount of K₂O or, alternatively, the glass composition may besubstantially free, as defined herein, of K₂O. In addition tofacilitating ion exchange, where applicable, in one or more embodiments,K₂O can also form a less durable phase or a degradable phase in theglass formed form the glass composition. The relationship between thedegradable phase(s) of the glass and antimicrobial activity is discussedin greater detail herein.

In one or more embodiments, the glass composition includes Na₂O in anamount in the range from about 0 to about 20, from about 0 to about 18,from about 0 to about 16, from about 0 to about 15, from about 0 toabout 14, from about 0 to about 13, from about 0 to about 12, from about0 to about 11, from about 0 to about 10, from about 0 to about 9, fromabout 0 to about 8, from about 0 to about 7, from about 0 to about 6,from about 0 to about 5, from about 0 to about 4, from about 0 to about3, from about 0 to about 2, from about 0 to about 1, from about 0.1 toabout 1, from about 0.2 to about 1, from about 0.3 to about 1 from about0.4 to about 1 from about 0.5 to about 1, from about 0 to about 0.5,from about 0 to about 0.4, from about 0 to about 0.3 from about 0 toabout 0.2, from about 0 to about 0.1 and all ranges and sub-rangestherebetween. In some embodiments, the glass composition includes anon-zero amount of Na₂O or, alternatively, the glass composition may besubstantially free, as defined herein, of Na₂O.

In one or more embodiments, the glass composition may include one ormore divalent cation oxides, such as alkaline earth oxides and/or ZnO.Such divalent cation oxides may be included to improve the meltingbehavior of the glass compositions. With respect to ion exchangeperformance, the presence of divalent cations can act to decrease alkalimobility and thus, when larger divalent cation oxides are utilized,there may be a negative effect on ion exchange performance. Furthermore,smaller divalent cation oxides generally help the compressive stressdeveloped in an ion-exchanged glass more than the larger divalent cationoxides. Hence, divalent cation oxides such as MgO and ZnO can offeradvantages with respect to improved stress relaxation, while minimizingthe adverse effects on alkali diffusivity.

In one or more embodiments, the glass composition includes CaO in anamount, in mole percent, in the range from about 0 to about 15, fromabout 0 to about 14, from about 0 to about 13, from about 0 to about 12,from about 0 to about 11, from about 0 to about 10, from about 0 toabout 9, from about 0 to about 8, from about 0 to about 7, from about 0to about 6, from about 0 to about 5, from about 0 to about 4, from about0 to about 3, from about 0 to about 2, from about 0 to about 1, fromabout 0.1 to about 1, from about 0.2 to about 1, from about 0.3 to about1 from about 0.4 to about 1 from about 0.5 to about 1, from about 0 toabout 0.5, from about 0 to about 0.4, from about 0 to about 0.3 fromabout 0 to about 0.2, from about 0 to about 0.1 and all ranges andsub-ranges therebetween. In some embodiments, the glass composition issubstantially free of CaO.

In one or more embodiments, the glass composition includes MgO in anamount, in mole percent, in the range from about 0 to about 15, fromabout 0 to about 14, from about 0 to about 13, from about 0 to about 12,from about 0 to about 11, from about 0 to about 10, from about 0 toabout 9, from about 0 to about 8, from about 0 to about 7, from about 0to about 6, from about 0 to about 5, from about 0 to about 4, from about0 to about 3, from about 0 to about 2, from about 0 to about 1, fromabout 0.1 to about 1, from about 0.2 to about 1, from about 0.3 to about1 from about 0.4 to about 1 from about 0.5 to about 1, from about 0 toabout 0.5, from about 0 to about 0.4, from about 0 to about 0.3 fromabout 0 to about 0.2, from about 0 to about 0.1 and all ranges andsub-ranges therebetween. In some embodiments, the glass composition issubstantially free of MgO.

The glass composition of one or more embodiments may include ZnO in anamount, in mole percent, in the range from about 0 to about 5, fromabout 0 to about 4, from about 0 to about 3, from about 0 to about 2,from about 0 to about 1, from about 0.1 to about 1, from about 0.2 toabout 1, from about 0.3 to about 1 from about 0.4 to about 1 from about0.5 to about 1, from about 0 to about 0.5, from about 0 to about 0.4,from about 0 to about 0.3 from about 0 to about 0.2, from about 0 toabout 0.1 and all ranges and sub-ranges therebetween. In someembodiments, the glass composition is substantially free of ZnO.

The glass composition of one or more embodiments may include Fe₂O₃, inmole percent, in the range from about 0 to about 5, from about 0 toabout 4, from about 0 to about 3, from about 0 to about 2, from about 0to about 1, from about 0.1 to about 1, from about 0.2 to about 1, fromabout 0.3 to about 1 from about 0.4 to about 1 from about 0.5 to about1, from about 0 to about 0.5, from about 0 to about 0.4, from about 0 toabout 0.3 from about 0 to about 0.2, from about 0 to about 0.1 and allranges and sub-ranges therebetween. In some embodiments, the glasscomposition is substantially free of Fe₂O₃.

In one or more embodiments, the glass composition may include one ormore colorants. Examples of such colorants include NiO, TiO₂, Fe₂O₃,Cr₂O₃, Co₃O₄ and other known colorants. In some embodiments, the one ormore colorants may be present in an amount in the range up to about 10mol %. In some instances, the one or more colorants may be present in anamount in the range from about 0.01 mol % to about 10 mol %, from about1 mol % to about 10 mol %, from about 2 mol % to about 10 mol %, fromabout 5 mol % to about 10 mol %, from about 0.01 mol % to about 8 mol %,or from about 0.01 mol % to about 5 mol %.

In one or more embodiments, the glass composition may include one ormore nucleating agents. Exemplary nucleating agents include TiO₂, ZrO₂and other known nucleating agents in the art. The glass composition caninclude one or more different nucleating agents. The nucleating agentcontent of the glass composition may be in the range from about 0.01 mol% to about 1 mol %. In some instances, the nucleating agent content maybe in the range from about 0.01 mol % to about 0.9 mol %, from about0.01 mol % to about 0.8 mol %, from about 0.01 mol % to about 0.7 mol %,from about 0.01 mol % to about 0.6 mol %, from about 0.01 mol % to about0.5 mol %, from about 0.05 mol % to about 1 mol %, from about 0.1 mol %to about 1 mol %, from about 0.2 mol % to about 1 mol %, from about 0.3mol % to about 1 mol %, or from about 0.4 mol % to about 1 mol %, andall ranges and sub-ranges therebetween.

The copper-containing glasses formed from the glass compositions mayinclude a plurality of Cu¹⁺ ions. In some embodiments, such Cu¹⁺ ionsform part of the glass network and may be characterized as a glassmodifier. Without being bound by theory, where Cu¹⁺ ions are part of theglass network, it is believed that during typical glass formationprocesses, the cooling step of the molten glass occurs too rapidly toallow crystallization of the copper-containing oxide (e.g., CuO and/orCu₂O). Thus the Cu¹⁺ remains in an amorphous state and becomes part ofthe glass network. In some cases, the total amount of Cu¹⁺ ions, whetherthey are in a crystalline phase or in the glass matrix, may be evenhigher, such as up to 40 mol %, up to 50 mol %, or up to 60 mol %.

In one or more embodiments, the copper-containing glasses formed formthe glass compositions disclosed herein include Cu¹⁺ ions that aredispersed in the glass matrix as Cu¹⁺ crystals. In one or moreembodiments, the Cu¹⁺ crystals may be present in the form of cuprite.The cuprite present in the copper-containing glass may form a phase thatis distinct from the glass matrix or glass phase. In other embodiments,the cuprite may form part of or may be associated with one or moreglasses phases (e.g., the durable phase described herein). The Cu¹⁺crystals may have an average major dimension of about 5 micrometers (μm)or less, 4 micrometers (μm) or less, 3 micrometers (μm) or less, 2micrometers (μm) or less, about 1.9 micrometers (μm) or less, about 1.8micrometers (μm) or less, about 1.7 micrometers (μm) or less, about 1.6micrometers (μm) or less, about 1.5 micrometers (μm) or less, about 1.4micrometers (μm) or less, about 1.3 micrometers (μm) or less, about 1.2micrometers (μm) or less, about 1.1 micrometers or less, 1 micrometersor less, about 0.9 micrometers (μm) or less, about 0.8 micrometers (μm)or less, about 0.7 micrometers (μm) or less, about 0.6 micrometers (μm)or less, about 0.5 micrometers (μm) or less, about 0.4 micrometers (μm)or less, about 0.3 micrometers (μm) or less, about 0.2 micrometers (μm)or less, about 0.1 micrometers (μm) or less, about 0.05 micrometers (μm)or less, and all ranges and sub-ranges therebetween. As used herein andwith respect to the phrase “average major dimension”, the word “average”refers to a mean value and the word “major dimension” is the greatestdimension of the particle as measured by SEM. In some embodiments, thecuprite phase may be present in the copper-containing glass in an amountof at least about 10 wt %, at least about 15 wt %, at least about 20 wt%, at least about 25 wt % and all ranges and subranges therebetween ofthe copper-containing glass.

In some embodiments, the copper-containing glass may include about 70 wt% Cu¹⁺ or more and about 30 wt % of Cu²⁺ or less. The Cu²⁺ ions may bepresent in tenorite form and/or even in the glass (i.e., not as acrystalline phase).

In some embodiments, the total amount of Cu by wt % in thecopper-containing glass may be in the range from about 10 to about 30,from about 15 to about 25, from about 11 to about 30, from about 12 toabout 30, from about 13 to about 30, from about 14 to about 30, fromabout 15 to about 30, from about 16 to about 30, from about 17 to about30, from about 18 to about 30, from about 19 to about 30, from about 20to about 30, from about 10 to about 29, from about 10 to about 28, fromabout 10 to about 27, from about 10 to about 26, from about 10 to about25, from about 10 to about 24, from about 10 to about 23, from about 10to about 22, from about 10 to about 21, from about 10 to about 20, fromabout 16 to about 24, from about 17 to about 23, from about 18 to about22, from about 19 to about 21 and all ranges and sub-rangestherebetween. In one or more embodiments, the ratio of Cu¹⁺ ions to thetotal amount Cu in the copper-containing glass is about 0.5 or greater,0.55 or greater, 0.6 or greater, 0.65 or greater, 0.7 or greater, 0.75or greater, 0.8 or greater, 0.85 or greater, 0.9 or greater or even 1 orgreater, and all ranges and sub-ranges therebetween. The amount of Cuand the ratio of Cu¹⁺ ions to total Cu may be determined by inductivelycoupled plasma (ICP) techniques known in the art.

In some embodiments, the copper-containing glass may exhibit a greateramount of Cu¹⁺ and/or Cu0 than Cu²⁺. For example, based on the totalamount of Cu¹⁺, Cu²⁺ and Cu0 in the glasses, the percentage of Cu¹⁺ andCu⁰, combined, may be in the range from about 50% to about 99.9%, fromabout 50% to about 99%, from about 50% to about 95%, from about 50% toabout 90%, from about 55% to about 99.9%, from about 60% to about 99.9%,from about 65% to about 99.9%, from about 70% to about 99.9%, from about75% to about 99.9%, from about 80% to about 99.9%, from about 85% toabout 99.9%, from about 90% to about 99.9%, from about 95% to about99.9%, and all ranges and sub-ranges therebetween. The relative amountsof Cu¹⁺, Cu²⁺ and Cu⁰ may be determined using x-ray photoluminescencespectroscopy (XPS) techniques known in the art. The copper-containingglass comprises at least a first phase and second phase. In one or moreembodiments, the copper-containing glass may include two or more phaseswherein the phases differ based on the ability of the atomic bonds inthe given phase to withstand interaction with a leachate. Specifically,the copper-containing glass of one or more embodiments may include afirst phase that may be described as a degradable phase and a secondphase that may be described as a durable phase. The phrases “firstphase” and “degradable phase” may be used interchangeably. The phrases“second phase” and “durable phase” may be used interchangeably. As usedherein, the term “durable” refers to the tendency of the atomic bonds ofthe durable phase to remain intact during and after interaction with aleachate. As used herein, the term “degradable” refers to the tendencyof the atomic bonds of the degradable phase to break during and afterinteraction with one or more leachates. In one or more embodiments, thedurable phase includes SiO₂ and the degradable phase includes at leastone of B₂O₃, P₂O₅ and R₂O (where R can include any one or more of K, Na,Li, Rb, and Cs). Without being bound by theory, it is believed that thecomponents of the degradable phase (i.e., B₂O₃, P₂O₅ and/or R₂O) morereadily interact with a leachate and the bonds between these componentsto one another and to other components in the copper-containing glassmore readily break during and after the interaction with the leachate.Leachates may include water, acids or other similar materials. In one ormore embodiments, the degradable phase withstands degradation for 1 weekor longer, 1 month or longer, 3 months or longer, or even 6 months orlonger. In some embodiments, longevity may be characterized asmaintaining antimicrobial efficacy over a specific period of time.

In one or more embodiments, the durable phase is present in an amount byweight that is greater than the amount of the degradable phase. In someinstances, the degradable phase forms islands and the durable phaseforms the sea surrounding the islands (i.e., the durable phase). In oneor more embodiments, either one or both of the durable phase and thedegradable phase may include cuprite. The cuprite in such embodimentsmay be dispersed in the respective phase or in both phases.

In some embodiments, phase separation occurs without any additional heattreatment of the copper-containing glass. In some embodiments, phaseseparation may occur during melting and may be present when the glasscomposition is melted at temperatures up to and including about 1600° C.or 1650° C. When the glass is cooled, the phase separation ismaintained.

The copper-containing glass may be provided as a sheet or may haveanother shape such as particulate (which may be hollow or solid),fibrous, and the like. In one or more embodiments, the copper-containingglass includes a surface and a surface portion extending from thesurface into the copper-containing glass at a depth of about 5nanometers (nm) or less. The surface portion may include a plurality ofcopper ions wherein at least 75% of the plurality of copper ionsincludes Cu¹⁺-ions. For example, in some instances, at least about 80%,at least about 85%, at least about 90%, at least about 95%, at leastabout 98%, at least about 99% or at least about 99.9% of the pluralityof copper ions in the surface portion includes Cu¹⁺ ions. In someembodiments, 25% or less (e.g., 20% or less, 15% or less, 12% or less,10% or less or 8% or less) of the plurality of copper ions in thesurface portion include Cu²⁺ ions. For example, in some instances, 20%or less, 15% or less, 10% or less, 5% or less, 2% or less, 1% or less,0.5% or less or 0.01% or less of the plurality of copper ions in thesurface portion include Cu²⁺ ions. In some embodiments, the surfaceconcentration of Cu¹⁺ ions in the copper-containing glass is controlled.In some instances, a Cu¹⁺ ion concentration of about 4 ppm or greatercan be provided on the surface of the copper-containing glass.

The copper-containing glass of one or more embodiments may a 2 logreduction or greater (e.g., 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5 and allranges and sub-ranges therebetween) in a concentration of at least oneof Staphylococcus aureus, Enterobacter aerogenes, Pseudomonasaeruginosa, Methicillin Resistant Staphylococcus aureus, and E. coli,under the EPA Test. In some instances, the copper-containing glassexhibits at least a 4 log reduction, a 5 log reduction or even a 6 logreduction in the concentration of at least one of Staphylococcus aureus,Enterobacter aerogenes, Pseudomonas aeruginosa bacteria, MethicillinResistant Staphylococcus aureus, and E. coli under the EPA Test.

The glasses described herein according to one or more embodiments mayexhibit a 4 log reduction or greater (e.g., 5 log reduction or greater)in a concentration of at least one of Staphylococcus aureus,Enterobacter aerogenes, Pseudomonas aeruginosa bacteria, MethicillinResistant Staphylococcus aureus, and E. coli, under JIS Z 2801 (2000)testing conditions. One or more embodiments of the glasses describedherein also exhibit a 4 log reduction or greater (e.g., 5 log reductionor greater) in a concentration of at least one of Staphylococcus aureus,Enterobacter aerogenes, Pseudomonas aeruginosa Methicillin ResistantStaphylococcus aureus, and E. coli, under the Modified JIS Z 2801 Testfor Bacterial. As used herein, Modified JIS Z 2801 Test for Bacteriaincludes evaluating the bacteria under the standard JIS Z 2801 (2000)test with modified conditions comprising heating the glass or article toa temperature of about 23 degrees Celsius to about 37 degrees Celsius ata humidity of about 38 percent to about 42 percent for about 6 hours.

In one or more embodiments described herein, the copper-containingglasses exhibit a 2 log reduction or greater, a 3 log reduction orgreater, a 4 log reduction or greater, or a 5 log reduction or greaterin Murine Norovirus under a Modified JIS Z 2801 for Viruses test. TheModified JIS Z 2801 (2000) Test for Viruses includes the followingprocedure. For each material (e.g., the articles or glass of one or moreembodiments, control materials, and any comparative glasses or articles)to be tested, three samples of the material (contained in individualsterile petri dishes) are each inoculated with a 20 μL aliquot of a testvirus (where antimicrobial activity is measured) or a test mediumincluding an organic soil load of 5% fetal bovine serum with or withoutthe test virus (where cytotoxicity is measured). The inoculum is thencovered with a film and the film is pressed down so the test virusand/or or test medium spreads over the film, but does not spread pastthe edge of the film. The exposure time begins when each sample wasinoculated. The inoculated samples are transferred to a control chamberset to room temperature (about 20° C.) in a relative humidity of 42% for2 hours. Exposure time with respect to control samples are discussedbelow. Following the 2-hour exposure time, the film is lifted off usingsterile forceps and a 2.00 mL aliquot of the text virus and/or testmedium is pipetted individually onto each sample of material and theunderside of the film (or the side of the film exposed to the sample)used to cover each sample. The surface of each sample is individuallyscrapped with a sterile plastic cell scraper to collect the test virusor test medium. The test virus and/or test medium is collected (at 10⁻²dilution), mixed using a vortex type mixer and serial 10-fold dilutionsare prepared. The dilutions are then assayed for antimicrobial activityand/or cytotoxicity.

To prepare a control sample for testing antimicrobial activity (whichare also referred to as “zero-time virus controls”) for the Modified JISZ 2801 Test for Viruses, three control samples (contained in individualsterile petri dishes) are each inoculated with a 20 μL aliquot of thetest virus. Immediately following inoculation, a 2.00 mL aliquot of testvirus is pipetted onto each control sample. The surface of each samplewas individually scrapped with a sterile plastic cell scraper to collecttest virus. The test virus is collected (at 10⁻² dilution), mixed usinga vortex type mixer, and serial 10-fold dilutions were prepared. Thedilutions are assayed for antimicrobial activity.

To prepare controls samples for cytotoxicity (which are also referred toas “2 hour control virus”) for the Modified JIS Z 2801 Test for Viruses,one control sample (contained in an individual sterile petri dish) isinoculated with a 20 μL aliquot of a test medium containing an organicsoil load (5% fetal bovine serum), without the test virus. The inoculumis covered with a film and the film is pressed so the test mediumspreads over the film but does not spread past the edge of the film. Theexposure time begins when each control sample is inoculated. The controlsample is transferred to a controlled chamber set to room temperature(20° C.) in a relative humidity of 42% for a duration of 2 hoursexposure time. Following this exposure time, the film is lifted offusing sterile forceps and a 2.00 mL aliquot of the test medium ispipetted individually onto each control sample and the underside of thefilm (the side exposed to the sample). The surface of each sample isindividually scrapped with a sterile plastic cell scraper to collect thetest medium. The test medium is collected (at 10⁻² dilution), mixedusing a vortex type mixer, and serial 10-fold dilutions were prepared.The dilutions were assayed for cytotoxicity.

The copper-containing glass of one or more embodiments may exhibit thelog reduction described herein for long periods of time. In other words,the copper-containing glass may exhibit extended or prolongedantimicrobial efficacy. For example, in some embodiments, thecopper-containing glass may exhibit the log reductions described hereinunder the EPA Test, the JIS Z 2801 (2000) testing conditions, theModified JIS Z 2801 Test for Bacteria and/or the Modified JIS Z 2801Test for Viruses for up to 1 month, up to 3 months, up to 6 months or upto 12 months after the copper-containing glass is formed or after thecopper-containing glass is combined with a carrier (e.g., polymers,monomers, binders, solvents and the like). These time periods may startat or after the copper-containing glass is formed or combined with acarrier.

In some embodiments, the material kills fungi (e.g., A. pullulans and A.niger/P. funiculosum) under ASTM 5590. In some embodiments, the materialkills such fungi under a zone of inhibition test, as described herein.

One or more embodiments, the copper-containing glass may exhibit apreservative function, when combined with carriers described herein. Insuch embodiments, the copper-containing glass may kill or eliminate, orreduce the growth of various foulants in the carrier. Foulants includefungi, bacteria, viruses and combinations thereof.

In one or more embodiments, the copper-containing glasses and/ormaterials described herein leach the copper ions when exposed or incontact with a leachate. In one or more embodiments, thecopper-containing glass leaches only copper ions when exposed toleachates including water.

In one or more embodiments, the copper-containing glass and/or articlesdescribed herein may have a tunable antimicrobial activity release. Theantimicrobial activity of the glass and/or materials may be caused bycontact between the copper-containing glass and a leachate, such aswater, where the leachate causes Cu¹⁺ ions to be released from thecopper-containing glass. This action may be described as watersolubility and the water solubility can be tuned to control the releaseof the Cu⁺¹ ions.

In some embodiments, where the Cu¹⁺ ions are disposed in the glassnetwork and/or form atomic bonds with the atoms in the glass network,water or humidity breaks those bonds and the Cu¹⁺ ions available forrelease and may be exposed on the glass or glass ceramic surface.

In one or more embodiments, the copper-containing glass may be formedusing formed in low cost melting tanks that are typically used formelting glass compositions such as soda lime silicate. Thecopper-containing glass may be formed into a sheet using formingprocesses known in the art. For instance, example forming methodsinclude float glass processes and down-draw processes such as fusiondraw and slot draw.

After formation, the copper-containing particles may be formed intosheets and may be shaped, polished or otherwise processed for a desiredend use. In some instances, the copper-containing glass may be ground toa powder or particulate form. In other embodiments, the particulatecopper-containing glass may be combined with other materials or carriersinto articles for various end uses. The combination of thecopper-containing glass and such other materials or carriers may besuitable for injection molding, extrusion or coatings or may be drawninto fibers.

In one or more embodiments, the copper-containing particles may includecuprous oxide. The amount of cuprous oxide in the particles may be up to100%. In other words, the cuprous oxide particles may exclude glass or aglass network.

In one or more embodiments, the copper-containing particles may have adiameter in the range from about 0.1 micrometers (μm) to about 10micrometers (μm), from about 0.1 micrometers (μm) to about 9 micrometers(μm), from about 0.1 micrometers (μm) to about 8 micrometers (μm), fromabout 0.1 micrometers (μm) to about 7 micrometers (μm), from about 0.1micrometers (μm) to about 6 micrometers (μm), from about 0.5 micrometers(μm) to about 10 micrometers (μm), from about 0.75 micrometers (μm) toabout 10 micrometers (μm), from about 1 micrometers (μm) to about 10micrometers (μm), from about 2 micrometers (μm) to about 10 micrometers(μm), from about 3 micrometers (μm) to about 10 micrometers (μm) fromabout 3 micrometers (μm) to about 6 micrometers (μm), from about 3.5micrometers (μm) to about 5.5 micrometers (μm), from about 4 micrometers(μm), to about 5 micrometers (μm), and all ranges and sub-rangestherebetween. As used herein, the term “diameter” refers to the longestdimension of the particle. The particulate copper-containing glass maybe substantially spherical or may have an irregular shape. The particlesmay be provided in a solvent and thereafter dispersed in a carrier asotherwise described herein.

In one or more embodiments, the copper-containing particles are presentin an amount of about 20 g/gallon or less. In some instances, thecopper-containing particles are present in an amount in the range fromabout 3.5 g/gallon to about 20 g/gallon, from about 4 g/gallon to about20 g/gallon, from about 5 g/gallon to about 20 g/gallon, from about 6g/gallon to about 20 g/gallon, from about 8 g/gallon to about 20g/gallon, from about 10 g/gallon to about 20 g/gallon, from about 3.5g/gallon to about 18 g/gallon, from about 3.5 g/gallon to about 16g/gallon, from about 3.5 g/gallon to about 15 g/gallon, from about 3.5g/gallon to about 14 g/gallon, from about 3.5 g/gallon to about 12g/gallon, from about 3.5 g/gallon to about 10 g/gallon, or from about 1g/gallon to about 4 g/gallon.

As mentioned above, the combination of the copper-containing particlesand Zn-PT show synergistic antimicrobial effect and allow the use ofCu-Glass at concentration that minimizes the color of the resultingmaterial (especially, when the carrier is a paint). In addition, thecombination improves antimicrobial performance when the material isapplied to a surface as a layer and exhibits strong antifungal activity.Without being bound by theory, it is believed that the such synergisticeffects are partially attributable to the formation of CuPT bytranschelation of ZnPT with Cu, and CuPT has been shown to be more toxicthan ZnPT to marine organisms. It is believed that pyrithione is ageneral inhibitor of membrane transport in fungi and inhibits membranetransport via a direct or indirect effect on the primary proton pump.

Further, it is believed that the combination of copper ions and ZnPTpermits lower biocide loading in a material, while maintaining strongantimicrobial performance and colorlessness. For example, as will bedemonstrated in the Examples below, a material including 4 g ofcopper-containing glass particles per gallon of carrier and 10 g ZnPTper gallon of carrier, exhibits improved antimicrobial performance over20 g ZnPT per gallon of carrier.

In contrast, to achieve the same level of antimicrobial activity usingsilver, higher amounts of silver are required. Moreover, silver leachesrapidly, thus reducing durability of the antimicrobial performance.Further, silver cannot be used in exterior applications since themoisture (e.g., rain) causes all of the silver to leach out of thematerial quickly.

In one or more embodiments, the carrier may include polymers, monomers,binders, solvents, or a combination thereof as described herein. In aspecific embodiment, the carrier is a paint that is used for applicationto surfaces (which may include interior or exterior surfaces).

The polymer used in the embodiments described herein can include athermoplastic polymer, a polyolefin, a cured polymer, an ultraviolet- orUV-cured polymer, a polymer emulsion, a solvent-based polymer, andcombinations thereof. Examples of suitable polymers include, withoutlimitation: thermoplastics including polystyrene (PS), high impact PS,polycarbonate (PC), nylon (sometimes referred to as polyamide (PA)),poly(acrylonitrile-butadiene-styrene) (ABS), PC-ABS blends,polybutyleneterephthlate (PBT) and PBT co-polymers,polyethyleneterephthalate (PET) and PET co-polymers, polyolefins (PO)including polyethylenes (PE), polypropylenes (PP), cyclicpolyolefins(cyclic-PO), modified polyphenylene oxide (mPPO), polyvinylchloride(PVC), acrylic polymers including polymethyl methacrylate (PMMA),thermoplastic elastomers (TPE), thermoplastic urethanes (TPU),polyetherimide (PEI) and blends of these polymers with each other.Suitable injection moldable thermosetting polymers include epoxy,acrylic, styrenic, phenolic, melamine, urethanes, polyesters andsilicone resins. In other embodiments, the polymers may be dissolved ina solvent or dispersed as a separate phase in a solvent and form apolymer emulsion, such as a latex (which is a water emulsion of asynthetic or natural rubber, or plastic obtained by polymerization andused especially in coatings (as paint) and adhesives. Polymers mayinclude fluorinated silanes or other low friction or anti-frictivematerials. The polymers can contain impact modifiers, flame retardants,UV inhibitors, antistatic agents, mold release agents, fillers includingglass, metal or carbon fibers or particles (including spheres), talc,clay or mica and colorants. Specific examples of monomers includecatalyst curable monomers, thermally-curable monomers, radiation-curablemonomers and combinations thereof.

To improve processability, mechanical properties and interactionsbetween the carrier and the copper-glass particles described herein(including any fillers and/or additives that may be used), processingagents/aids may be included in the articles described herein. Exemplaryprocessing agents/aids can include solid or liquid materials. Theprocessing agents/aids may provide various extrusion benefits, and mayinclude silicone based oil, wax and free flowing fluoropolymer. In otherembodiments, the processing agents/aids may includecompatibilizers/coupling agents, e.g., organosilicon compounds such asorgano-silanes/siloxanes that are typically used in processing ofpolymer composites for improving mechanical and thermal properties. Suchcompatibilizers/coupling agents can be used to surface modify the glassand can include (3-acryloxy-propyl)trimethoxysilane; N-(2-aminoethyl)-3-aminopropyltrimethoxysilane; 3-aminopropyltri-ethoxysilane;3-aminopropyltrimethoxysilane; (3-glycidoxypropyl)trimethoxysilane;3-mercaptopropyltrimethoxysilane; 3-methacryloxypropyltrimethoxysilane;and vinyltrimethoxysilane.

In some embodiments, the materials described herein may include fillersincluding pigments, that are typically metal based inorganics can alsobe added for color and other purposes, e.g., aluminum pigments, copperpigments, cobalt pigments, manganese pigments, iron pigments, titaniumpigments, tin pigments, clay earth pigments (naturally formed ironoxides), carbon pigments, antimony pigments, barium pigments, and zincpigments.

After combining the copper-containing glass described herein with acarrier, as described herein, the combination or resulting material maybe formed into a desired article or be applied to a surface. Where thematerial includes paint, the paint may be applied to a surface as alayer. Examples of such articles that may be formed using the materialdescribed herein include housings for electronic devices (e.g., mobilephones, smart phones, tablets, video players, information terminaldevices, laptop computer, etc.), architectural structures (e.g.,countertops or walls), appliances (e.g., cooktops, refrigerator anddishwasher doors, etc.), information displays (e.g., whiteboards), andautomotive components (e.g., dashboard panels, windshields, windowcomponents, etc.).

The materials described herein may include pigments to impart color.Accordingly, the coatings or layers made from such materials may exhibita wide variety of colors, depending on the carrier color, mixture ofcarriers and amount of particle loading. Moreover, the materials and/orcoatings described herein showed no adverse effect to paint adhesion asmeasured by ASTM D4541. In some instances, the adhesion of the materialor coating to an underlying substrate was greater than the cohesivestrength of the substrate. In other words, in testing, the adhesionbetween the coating or coating and the substrate was so strong that theunderlying substrate failed before the coating was separated from thesurface of the substrate. For example, where the substrate includeswood, the adhesion between the coating or layer and the substrate may beabout 300 psi or greater, 400 psi or greater, 500 psi or greater, 600psi or greater and all ranges-sub-ranges therebetween, as measured byASTM D4541. In some instances, the material, when applied to a substrateas a coating or layer, exhibits an anti-sag index value of about 3 orgreater, about 5 or greater, 7 or greater, 8 or greater, 9 or greater,10 or greater, 11 or greater, 12 or greater, 13 or greater, 14 orgreater or even 15 or greater, as measured by ASTM D4400.

The material and/or coating may exhibit sufficient durability for use inhousehold and commercial applications. Specifically, the material, whenapplied to a substrate as a coating or layer, exhibits a scrubresistance as measured by ASTM D4213 of about 4 or greater, 5 orgreater, 6 or greater, 7 or greater and all ranges and sub-rangestherebetween.

In one or more embodiments, the material and/or coating may be resistantto moisture. For example, after exposure of the material and/or coatingto an environment of up to about 95% relative humidity for 24 hours, thematerial and/or coating exhibited no change in antimicrobial activity.

One or more embodiments of the material may include an copper-containingglass and a carrier with a loading level of the copper-containing glasssuch that the material exhibits resistance or preservation against thepresence or growth of foulants. Foulants include fungi, bacteria,viruses and combinations thereof. In some instances, the presence orgrowth of foulants in materials, such as paints, varnishes and the like,can cause color changes to the material, can degrade the integrity ofthe material and negatively affect various properties of the material.By including a minimum loading of copper-containing glass, (e.g., about5 wt % or less, about 4 wt % or less, about 3 wt % or less, about 2 wt %or less, or about 1 wt % or less) to the carrier, the foulants can beeliminated or reduced. In some instances, the carrier formulation neednot include certain components, when fouling is eliminated or reduced.Thus, the carrier formulations used in one or more embodiments of thematerials described herein may have more flexibility and variations thanpreviously possible, when in known materials that do not include thecopper-containing glass.

EXAMPLES

Various embodiments will be further clarified by the following examples.

Example 1

Examples 1A-1F were prepared to evaluate fungi growth control under ASTM5590. Examples 1A-1F included the formulations shown in Table 1. Thecopper-containing glass particles used in Examples 1B-1F included acomposition of 45 mol % SiO₂, 35 mol % CuO, 7.5 mol % K₂O, 7.5 mol %B₂O₃ and 5 mol % P₂O₅.

TABLE 1 Examples 1A-1F. Example Carrier Biocide 1 Biocide 2 1A (Compar-Biocide-free control None None ative) paint A 1B (Compar- Biocide-freecontrol Copper-containing None ative) paint A glass, 5 g/gallon carrier1C (Compar- Biocide-free control Copper-containing None ative) paint Aglass, 10 g/gallon carrier 1D (Compar- Biocide-free control None ZnPT 10ative) paint A g/gallon carrier 1E Biocide-free controlCopper-containing ZnPT 10 paint A glass, 4 g/gallon g/gallon carriercarrier 1F Biocide-free control Copper-containing ZnPT 10 paint A glass,10 g/gallon g/gallon carrier carrier

The paints of Examples 1A-1F were applied onto identical papersubstrates and exposed to A. pullalans (mold) or A. niger/P. funiculosum(mildew) by direct contact with suspensions of the relevant fungi. Theinoculated samples were placed in a sealed and humid environment at 30°C./saturated humidity, and incubated for 28 days. Anti-fungalperformance was determined by visual assessment of the percentage offungal growth on the paint. Based on the percentage of the growthobserved, a numerical score was assigned to each substance: 0=No growth,1=trace of growth (less than 10%), 2=light growth (10 to 30%), 3=Mediumgrowth (30-60%), 4=heavy growth (60% to complete coverage). Table 2shows the results after 3 weeks.

TABLE 2 ASTM 5590 results after 3 weeks. Example A. pullalans A.niger/P. funiculosum 1A (Comparative) 4 4 1B (Comparative) 4 4 1C(Comparative) 4 4 1D (Comparative) 3 0 1E 0 0 1F 0 0

As shown in Table 2, paints including both ZnPT and copper ionsexhibited superior performance.

Example 2

The amount of ZnPT and copper-containing glass necessary to inhibitfungi growth was evaluated. The copper-containing glass had the samecomposition as used in Examples 1A-1F. As shown in FIGS. 1 and 2, thecombination of ZnPT and copper-containing glass inhibits fungi growth atsmaller amounts than ZnPT alone. FIG. 1 shows that only 1 g/gallon ofZnPT and copper-containing glass is needed to reduce mold growth (versus10 g/gallon of ZnPT alone). FIG. 2 shows only 10 g/gallon of ZnPT andcopper-containing glass is needed to reduce mildew growth (versus 100g/gallon of ZnPT alone).

Example 3

The color of paint including ZnPT and copper-containing glass wasevaluated. Examples 3A-3D included the same biocide-free control paint Aused in Example 1. Example 3A did not include any ZnPT orcopper-containing glass particles. Examples 3B-3D included 1 g/gallon, 5g/gallon and 10 g/gallon copper-containing glass particles,respectively. None of Examples 3A-3D included ZnPT. As shown in Table 3,minimal color change was observed at concentrations up to 10 g/gallon.Delta E in Table 3 is with respect to the color coordinates of Example3A. Specifically Delta E for each of Examples 3B-3D was determined usingthe equation: √(L*−L*_(Ex. 3A))²+(a*−a*_(Ex. 3A))²+(b*−b*_(Ex. 3A))²).

TABLE 3 L*, a*, b* and Delta E values, with respect to the Example 3A,for Examples 3A-3D. Ex. L* a* b* Delta E Comparative Ex. 96.46 −0.031.58 3A Ex. 3B 96.53 0.08 2.03 0.47 Ex. 3C 95.86 0.44 2.79 1.43 Ex. 3D95.09 1.22 4.14 3.16

Example 4

Anti-microbial performance was also evaluated using a zone of inhibitiontest of S. aureus, which is derived based on the Kirby-Bauer antibiotictesting (KB testing or disc diffusion antibiotic sensitivity testing).The KB testing uses antibiotic-impregnated wafers to test whetherbacteria are affected by antibiotics. In Example 1, painted papersubstrates containing co-biocides are placed on an agar plate where A.pullalans (mold) or A. niger/P. funiculosum (mildew) was spreadbeforehand. Each plate is incubated overnight at 37° C. If a biocidestops the bacteria from growing or kills the bacteria, there will be anarea around the substrate where the bacteria have not grown enough to bevisible; this area is referred to as the zone of inhibition. The size ofthis zone depends on how effective the biocide is at stopping the growthof the bacterium. A stronger biocide will create a larger zone, becausea lower concentration of the biocide is enough to stop growth.

Examples 4A-4E were prepared using identical biocide-free paint.Comparative Example 4A included no ZnPT or copper-containing glassparticles. Comparative Example 4B included 15 mg/gallon ZnPT but nocopper-containing glass particles. Comparative Example 4C included 10g/gallon of the same copper-containing glass particles used in Example 1but no ZnPT. Examples 4D and 4E both included 15 mg/gallon ZnPT and 4g/gallon and 10 g/gallon of the same copper-containing glass particlesused in Example 1, respectively. As shown in FIG. 3, Examples 4D and 4Eperformed better than Comparative Examples 4A-4C, under the zone ofinhibition test.

It will be apparent to those skilled in the art that variousmodifications and variations can be made without departing from thespirit or scope of the invention.

What is claimed is:
 1. A material comprising: a carrier; and aco-biocide including a plurality of copper-containing particles andeither one or both of ZnPT and Tralopyril, wherein the ratio of thecopper-containing particles (g) and either one or both of ZnPT andTralopyril (g) per gallon of carrier is in the range from about 0.005 toabout 12 wherein the copper-containing particles comprise either one orboth of copper-containing glass and cuprous oxide, and further whereinthe copper-containing glass comprises a cuprite phase comprising aplurality of Cu¹⁺ ions, and comprising at least one of B₂O₃, P₂O₅ andR₂O.
 2. The material of claim 1, wherein either one or both of ZnPT andTralopyril is present in a range from about 150 mg/gallon of carrier toabout 40 g/gallon of carrier.
 3. The material of claim 1, furthercomprising Zn, wherein ZnPT is in an excess amount.
 4. The material ofclaim 1, wherein the copper-containing particles are present in anamount of about 20 g/gallon or less.
 5. The material of claim 1, furthercomprising a glass phase comprising more than 40 mol % SiO₂, and whereinthe cuprite phase is dispersed in the glass phase.
 6. The material ofclaim 5, wherein the cuprite phase is degradable and leaches in thepresence of water.
 7. The material of claim 1, wherein the carriercomprises a polymer, a monomer, a binder or a solvent.
 8. The materialof claim 1, wherein the material exhibits a greater than 3 log reductionin a concentration of Staphylococcus aureus, under the EPA Test Methodfor Efficacy of Copper Alloy as a Sanitizer testing conditions.